*{
	padding:0;
	margin:0;
	list-style:none;
}
.banner{margin:100px auto;border:5px solid #000;width:550px;height:300px;position:relative; overflow:hidden;}
 img{width:550px;height:300px;}
.banner .img{width:5000px;
              position:absolute;
			   left:0;}
.banner .img li{float:left;
              }
.banner:hover .btn{
	display:block;
}
.banner .num{
	position:absolute;
	width:100%;
	bottom:10px;
	left:0;
	text-align:center;
	font-size:0;
}
.banner .num  li{
	width:10px;
	height:10px;
	background:#888;
	border-radius:50%;
	display:inline-block;
	margin:0 3px;
	cursor:pointer;
}
.banner .num .on{
 background:#F60;
}

.banner .btn{
	width:30px;
	height:50px;
	background:rgba(0,0,0,0.5);
	position:absolute;
	top:50%;
	margin-top:-25px;
	cursor:pointer;
	text-align:center;
	line-height:50px;
	color:#fff;
	font-size:40px;
	display:none;

    
}
.banner .btn_l{
	left:0;
}
.banner .btn_r{
	right:0;
}
